Do While loop in JavaScript

Program 1

"use strict"
const ps=require("prompt-sync")
const prompt=ps({sigint:true})
let choice
do
{
   console.log("-------------Menu-------------")
   console.log("1.Addtion")
   console.log("2.Swap")
   console.log("3.Factorial")
   console.log("4.Exit")
   console.log("--------------------------------")
   choice=parseInt(prompt("Enter your choice"))
   switch(choice)
   {
     case 1:
        {
            let a,b,c
            a=parseInt(prompt("Enter first number"))
            b=parseInt(prompt("Enter first number"))
            c=a+b
            console.log("Addtion is "+c)
            break
        }

        case 2:
        {
            let a,b,c
            a=parseInt(prompt("Enter first number"))
            b=parseInt(prompt("Enter first number"))
             console.log("Before Swaping: " + a + "  " + b)
             c=a
             a=b
             b=c
             console.log("After Swaping: " + a + "  " + b)
            break
        }
        case 3:
            {
                let n,f=1
                n=parseInt(prompt("Enter a number"))
                while(n!=0)
                {
                    f=f*n
                    n--
                }
                console.log("Factorial is : "+f)
            }
    }          
}while(choice!=4)



// let i=15
// console.log("while");
// while(i<=10)  // condition
// {
//     console.log(i)
//     i++;
// }
// console.log("Do while");
// let j=15;
// do
// {
//     console.log(j)
//     j++;
// }while(j<=10);